// -*- C++ -*-
-/* This file is part of
- * =================================================
- *
- * LyX, The Document Processor
- * Copyright 1995 Matthias Ettrich.
- * Copyright 1995-2001 The LyX Team.
+/**
+ * \file GraphicsCacheItem.h
+ * This file is part of LyX, the document processor.
+ * Licence details can be found in the file COPYING.
*
- * This file Copyright 2000 Baruch Even
- * ================================================= */
+ * \author Baruch Even
+ * \author Angus Leeming
+ *
+ * Full author contact details are available in file CREDITS.
+ *
+ * The graphics cache is a container of graphics::CacheItems.
+ * Each graphics::CacheItem, defined here represents a separate image file.
+ *
+ * The routines here can be used to load the graphics file into memory at
+ * which point (status() == graphics::Loaded).
+ * The user is then free to access image() in order to copy it and to then
+ * transform the copy (rotate, scale, clip) and to generate the pixmap.
+ *
+ * The graphics cache supports fully asynchronous:
+ * file conversion to a loadable format;
+ * file loading.
+ *
+ * Whether you get that, of course, depends on graphics::Converter and
+ * on the graphics::Image-derived image class.
+ */
#ifndef GRAPHICSCACHEITEM_H
#define GRAPHICSCACHEITEM_H
-#ifdef __GNUG__
-#pragma interface
-#endif
+#include "GraphicsTypes.h"
+
+#include <boost/signals2.hpp>
-#include XPM_H_LOCATION
-#include "LString.h"
-#include <boost/utility.hpp>
-#include <boost/smart_ptr.hpp>
+namespace lyx {
-#include <sigc++/signal_system.h>
+namespace support { class FileName; }
-class LyXImage;
+namespace graphics {
-/// A GraphicsCache item holder.
-class GraphicsCacheItem : boost::noncopyable {
+class Image;
+class Converter;
+
+/// A graphics::Cache item holder.
+class CacheItem {
public:
- /// c-tor
- GraphicsCacheItem(string const & filename);
- /// d-tor, frees the image structures.
- ~GraphicsCacheItem();
-
- /// Return a pixmap that can be displayed on X server.
- LyXImage * getImage() const;
///
- enum ImageStatus {
- ///
- Loading = 1,
- ///
- ErrorConverting,
- ///
- ErrorReading,
- ///
- UnknownError,
- ///
- Loaded
- };
-
- /// Is the pixmap ready for display?
- ImageStatus getImageStatus() const;
-
- /** Get a notification when the image conversion is done.
- used by an internal callback mechanism.
- */
- void imageConverted(bool success);
+ CacheItem(support::FileName const & file);
+ /// Needed for the pimpl
+ ~CacheItem();
-private:
- /** Start image conversion process, checks first that it is necessary
- * if necessary will start an (a)synchronous task and notify upon
- * completion by calling imageConverted(bool) where true is for success
- * and false is for a failure.
- *
- * Returns a bool to denote success or failure of starting the conversion
- * task.
+ ///
+ support::FileName const & filename() const;
+
+ /// Try to load a display format.
+ bool tryDisplayFormat() const;
+
+ /// It's in the cache. Now start the loading process.
+ void startLoading() const;
+
+ /** Monitor any changes to the file.
+ * There is no point monitoring the file before startLoading() is
+ * invoked.
*/
- bool convertImage(string const & filename);
-
- /// Load the image into memory, this gets called from imageConverted(bool).
- void loadImage();
-
- /// Sets the status of the image, in the future will also notify listeners
- /// that the status is updated.
- void setStatus(ImageStatus new_status);
-
- /** The filename we refer too.
- This is used when removing ourselves from the cache.
- */
- string filename_;
- /// The temporary file that we use
- string tempfile;
- /// The image status
- ImageStatus imageStatus_;
- /// The image (if it got loaded)
- boost::scoped_ptr<LyXImage> image_;
+ void startMonitoring() const;
+ ///
+ bool monitoring() const;
+ /** Returns the check checksum of filename() so that, for example, you can
+ * ascertain whether to output a new PostScript version of the file
+ * for a LaTeX run.
+ */
+ unsigned long checksum() const;
+
+ /** Get the image associated with filename().
+ * If the image is not yet loaded, returns 0.
+ * This routine returns a pointer to const; if you want to modify it,
+ * create a copy and modify that.
+ */
+ Image const * image() const;
+
+ /// How far have we got in loading the image?
+ ImageStatus status() const;
+
+ /** Connect and you'll be informed when the loading status of the image
+ * changes.
+ */
+ typedef boost::signals2::signal<void()> sig_type;
+ typedef sig_type::slot_type slot_type;
+ ///
+ boost::signals2::connection connect(slot_type const &) const;
+
+private:
+ /// noncopyable
+ CacheItem(CacheItem const &);
+ void operator=(CacheItem const &);
+
+ /// Use the Pimpl idiom to hide the internals.
+ class Impl;
+ /// The pointer never changes although *pimpl_'s contents may.
+ Impl * const pimpl_;
};
-#endif
+} // namespace graphics
+} // namespace lyx
+
+#endif // GRAPHICSCACHEITEM_H
projects / lyx.git / blobdiff